The invention relates to a method and an apparatus for absorbing lateral sideframe vibration in printing units.
Lateral vibration can cause noticeable sway in newspaper towers. If the sway becomes large enough, it can cause high stresses at connection points of printing units. Such sway can also lead to the discomfort of press operators and can introduce a lateral double into the print.
It is accordingly an object of the invention to provide a method and an apparatus for absorbing lateral sideframe vibration in printing units, which overcome the hereinafore-mentioned disadvantages of the heretofore-known methods and apparatuses of this general type and which damp vibrations and eliminate stresses leading to sway, so as to make the press more user friendly and improve the printed product.
With the foregoing and other objects in view there is provided, in accordance with the invention, an apparatus for absorbing lateral sideframe vibration in printing units, comprising a member connected between two sideframes of a printing unit; and a mass movably disposed on the member.
In accordance with another feature of the invention, the member is a rod connected between the sideframes, and the mass slides on the rod. Two springs each have one end connected to the mass and another end fixed relative to a respective one of the sideframes. The springs are disposed on the rod and have equal stiffness coefficients. A hollow unit frame tie is connected between the sideframes and surrounds the rod. The mass can therefore move along the rod to find the location at which vibration absorption best takes place.
In accordance with a further feature of the invention, there are provided collars each moveable on the rod between the other end of a respective one of the springs and a respective one of the sideframes. The rod is at least partly externally threaded, and the collars are internally threaded. This permits the preload in the springs to be manually adjusted. At least one additional mass is removably attached to the mass sliding on the rod. This feature also permits adjustment of the absorption apparatus. The use of collars also allows for ease of assembly by permitting parts to be installed loose and then tightened until preload is ensured. Collars allow springs to be easily changed in order to change spring rate of the system.
In accordance with an added feature of the invention, the member is a unit frame tie connected between the sideframes, and the mass is movable relative to the unit frame tie. A rod is connected to the unit frame tie and the mass is movable along the rod. The rod is externally threaded and the mass is internally threaded. The absorption apparatus can be adjusted in this way as well.
With the objects of the invention in view, there is also provided a method for absorbing lateral sideframe vibration in printing units, which comprises connecting a member between two sideframes of a printing unit; and placing a movable mass on the member.
In accordance with another mode of the invention, there is provided a method which comprises providing a rod as the member, and permitting the mass to slide on the rod. The mass is biased between two springs each having one end connected to the mass and another end fixed relative to a respective one of the sideframes. A hollow unit frame tie is disposed around the rod between the sideframes.
In accordance with a further mode of the invention, there is provided a method which comprises placing moveable collars on the rod. Each collar is disposed between the other end of a respective one of the springs and a respective one of the sideframes, for adjusting a preload of the springs. At least one additional mass may be removably attached to the mass sliding on the rod.
In accordance with a concomitant mode of the invention, there is provided a method which comprises providing a unit frame tie as the member, and moving the mass relative to the unit frame tie. A rod is connected to the unit frame tie, and the mass is moved along the rod.
Other features which are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in a method and an apparatus for absorbing lateral sideframe vibration in printing units, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.